Galvanizing is a corrosion protection process for steel, in which the steel is coated with zinc to prevent it from rusting. The process involves dipping cleaned iron or steel components into molten zinc (which is usually around 450°C). A series of zinc-iron alloy layers are formed by a metallurgical reaction between the iron and zinc creating a strong bond between steel and the coating. A typical time of immersion is about four or five minutes, but it can be longer for heavy articles that have high thermal inertia or where the zinc is required to penetrate internal voids.
Upon withdrawal from the galvanizing bath, a layer of molten zinc will be deposited on top of the alloy layer. Often this cools to exhibit the bright shiny appearance associated with galvanized products.
In reality, there is no demarcation between steel and zinc but a gradual transition through the series of alloy layers which provide the metallurgical bond. Conditions in the galvanizing plant such as temperature, humidity and air quality, do not affect the quality of the galvanized coating.